Also published as: Amaya L Rogers, Brianne B Rogers, Christopher S Rogers, Deborah J Rogers, Elizabeth S Rogers, Evan M Rogers, Hannah M Rogers, Maximillian A Rogers, Michael J Rogers, Miranda Rogers, Nicole H Rogers, Pamela M Rogers, Peter A W Rogers, Sally Rogers, Stephen L Rogers, Ursula Rogers, Walker D Rogers
Bidhan Bhandari, Sahar Emami Naeini, Hannah M Rogers+8 more · 2026 · Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco · Oxford University Press · added 2026-04-24
Nicotine pouches are rapidly increasing in popularity, yet their long-term neurological consequences remain poorly understood. Emerging evidence suggests nicotine may influence seizure susceptibility Show more
Nicotine pouches are rapidly increasing in popularity, yet their long-term neurological consequences remain poorly understood. Emerging evidence suggests nicotine may influence seizure susceptibility and neuroimmune signaling, while cannabidiol (CBD) has demonstrated neuroprotective and anti-inflammatory effects. This study investigated the time-dependent impact of acute versus chronic oral nicotine exposure on seizure vulnerability, neuroinflammation, and glymphatic function, and evaluated whether inhaled CBD can reverse these pathological changes. Mice were exposed to acute or 7-day chronic nicotine pouch prior to kainic acid-induced seizures. Seizure severity was scored using the Racine scale. Neuroinflammatory markers (IL-6, HMGB1), neuronal activation markers (BDNF, c-FOS), and Aquaporin-4 (AQP4) expression were quantified via flow cytometry, immunofluorescence, and western blotting. Glymphatic function was assessed using cisterna magna injection of rhodamine dextran tracers. An ex vivo IL-6 modulation assay evaluated nicotine-induced cytokine production and CBD-mediated suppression, with or without IL-6 receptor blockade. Acute nicotine transiently reduced seizure severity, whereas chronic exposure significantly exacerbated seizures, elevated IL-6, HMGB1, BDNF, and c-FOS, and markedly downregulated AQP4. CSF tracer studies confirmed impaired glymphatic influx following chronic nicotine exposure. CBD inhalation effectively reversed seizure severity restored AQP4 expression, normalized IL-6 and HMGB1 levels, and reduced c-FOS protein expression. The IL-6R blockade assay showed that nicotine induces IL-6 production in brain-derived immune cells, while CBD suppresses this response upstream of IL-6 signaling. Chronic nicotine pouch exposure promotes seizure susceptibility through converging neuroimmune and glymphatic disruptions. Inhaled CBD counteracts these effects, supporting its potential as a targeted therapeutic strategy for nicotine-associated neurological risk. This study provides the first evidence that chronic nicotine pouch exposure disrupts glymphatic function, amplifies neuroinflammation, and increases seizure susceptibility through an IL-6-centered neuroimmune network. These findings challenge the perception of nicotine pouches as low-risk products and highlight previously unrecognized neurological vulnerabilities associated with long-term use. The ability of inhaled CBD to reverse these pathological effects identifies a promising therapeutic strategy and underscores the need for further investigation into neuroimmune-glymphatic interactions in nicotine-related brain health. Show less
Posttraumatic stress disorder (PTSD) has been associated with accelerated cognitive aging and increased risk for Alzheimer's disease (AD) and related dementias (ADRD), yet the neural substrates linkin Show more
Posttraumatic stress disorder (PTSD) has been associated with accelerated cognitive aging and increased risk for Alzheimer's disease (AD) and related dementias (ADRD), yet the neural substrates linking trauma-related psychiatric illness to late-life neurodegenerative vulnerability remain poorly defined. The amygdala plays a central role in threat processing and emotional memory and exhibits persistent hyperactivity in PTSD, but its molecular and pathological state in aging individuals with PTSD has not been systematically examined. Postmortem amygdala tissue from older adult donors (≥ 70 years) with lifetime PTSD (n = 5) and age-matched controls (n = 5) was obtained from the National PTSD Brain Bank. A multimodal analysis was performed integrating immunohistochemical quantification of β-amyloid and phosphorylated tau pathology, targeted transcriptional profiling of AD-related genes, gene network analysis, and protein quantification of pathological, inflammatory, and synaptic markers. PTSD cases showed enrichment of combined tau-amyloid pathology within the amygdala and significantly greater β-amyloid burden. Targeted transcriptomic profiling identified coordinated upregulation of AD-related genes involved in amyloid processing, lipid metabolism, proteostasis, and inflammatory signaling. Network analysis revealed an APP-centered molecular architecture with APOE, MAPT, and CLU functioning as highly connected secondary hubs. Protein analyses demonstrated increased amyloid-β and pTau231 abundance, selective markers of gliosis, and synaptic alterations characterized by elevated excitatory receptor expression and reduced inhibitory GABABR1a. Older adults with PTSD exhibit convergent evidence of AD-relevant molecular and pathological remodeling in the amygdala. These findings suggest that chronic trauma-related circuit dysregulation may intersect with aging-associated inflammatory and synaptic processes, creating a biological environment permissive for neurodegenerative vulnerability in emotionally salient brain circuits. Show less
Tau neurofibrillary tangles are a hallmark of several neurodegenerative diseases called tauopathies, including frontotemporal dementia and Alzheimer's Disease. Ongoing clinical trials for tauopathies Show more
Tau neurofibrillary tangles are a hallmark of several neurodegenerative diseases called tauopathies, including frontotemporal dementia and Alzheimer's Disease. Ongoing clinical trials for tauopathies seek to reduce Tau in the brain through immunotherapy, antisense oligonucleotides, and siRNA. Show less
Complex PTSD (CPTSD) is often associated with prolonged or repeated trauma exposure and the experience of intimate partner and childhood abuse. CPTSD includes the criteria for PTSD (re-experiencing, a Show more
Complex PTSD (CPTSD) is often associated with prolonged or repeated trauma exposure and the experience of intimate partner and childhood abuse. CPTSD includes the criteria for PTSD (re-experiencing, avoidance, and sense of threat) in addition to three criteria for self-organization disturbances (affective dysregulation, negative self-concept, and relational disturbance). This study aimed to assess profiles of CPTSD symptoms and their association with psychiatric distress among people with co-occurring Serious Mental Illness (SMI; schizophrenia/schizoaffective, bipolar, and treatment-refractory major depression). Treatment-seeking participants ( A model with three classes best fit the data with the most parsimonious interpretation: 26.7% ( The results demonstrate the heterogeneity in symptom presentation across the PTSD classes and that, despite similar diagnoses, individuals may present with varying symptom patterns. This emphasizes the importance of studying CPTSD in subpopulations of persons with SMI. Show less
Alcohol-induced peripheral neuropathy (AIPN) is a painful and prevalent condition associated with chronic alcohol use, yet its molecular underpinnings remain poorly understood. Because the analgesic e Show more
Alcohol-induced peripheral neuropathy (AIPN) is a painful and prevalent condition associated with chronic alcohol use, yet its molecular underpinnings remain poorly understood. Because the analgesic effects of ethanol may reinforce alcohol consumption, elucidating the mechanisms driving AIPN is essential. This study aimed to identify ethanol-regulated gene expression patterns in the nervous system of a mouse model of AIPN. Male (n = 10) and female (n = 12) C57BL/6J mice were administered either an ethanol-containing Lieber-DeCarli liquid diet at 5% or an isocaloric control diet for four weeks. Ethanol consumption was recorded daily for the experimental group. After the drinking protocol, spinal cord and dorsal root ganglia tissues were collected for RNA sequencing. Ethanol-regulated genes were identified for each sex-tissue group using DESeq2, and results were compared to known rodent neuropathic pain gene signatures. Weighted gene co-expression network analysis (WGCNA) identified modules of co-expressed genes associated with ethanol administration. Hub genes with high intramodular connectivity were identified for ethanol-correlated modules. Of the 14 identified hub genes, 10 have been previously implicated in pain or neuropathy, including These findings provide novel insights into the gene networks underlying AIPN and nominate specific genes for future functional studies. Show less
Microtubule-actin cross-linking factor 1 (MACF1) is a large protein of the spectraplakin family, which is essential for brain development. MACF1 interacts with microtubules through the growth arrest-s Show more
Microtubule-actin cross-linking factor 1 (MACF1) is a large protein of the spectraplakin family, which is essential for brain development. MACF1 interacts with microtubules through the growth arrest-specific 2 (Gas2)-related (GAR) domain. Heterozygous MACF1 missense variants affecting the zinc-binding residues in this domain result in a distinctive cortical and brain stem malformation. Evidence for other MACF1-associated disorders is still limited. Here, we present a cohort of 45 individuals with heterozygous or bi-allelic MACF1 variants to explore the phenotypic spectrum and assess possible pathogenic relevance. We observe that de novo heterozygous missense variants in the EF-hand domains also result in distinctive brain malformation and provide experimental evidence that variants in the EF-hand/GAR module increase microtubule binding, suggestive of a toxic gain of function. Notably, no phenotype-genotype correlation was possible for the remaining heterozygous variants in other domains. A clinical review of eight families with bi-allelic variants reveals a possible complex neurodevelopmental syndrome of the central and peripheral nervous systems. In these individuals, bi-allelic variants mostly affect the Plakin domain. Furthermore, RNA sequencing and chromatin immunoprecipitation (ChIP) analyses of human fetal brain tissue reveal five MACF1 isoforms with region-specific expression, differing in their exon 1 transcription start sites but splicing to a common exon 2. This differential expression explains the frontal-predominant lissencephaly in an individual with a homozygous stop-gain in exon 1 (MACF1-204: c.70C>T [p.Arg24∗]), as this isoform is preferentially expressed in the frontal cortex. We conclude that MACF1-related disorders are strictly linked to domain function and the level of transcript expression, explaining the observed wide clinical heterogeneity. Show less
G-quadruplexes (G4s) are secondary DNA and RNA structures stabilized by positive cations in a central channel formed by stacked tetrads of Hoogsteen base-paired guanines. G4s form from G-rich sequence Show more
G-quadruplexes (G4s) are secondary DNA and RNA structures stabilized by positive cations in a central channel formed by stacked tetrads of Hoogsteen base-paired guanines. G4s form from G-rich sequences across the genome, whose biased distribution in regulatory regions points towards a gene-regulatory role. G4s can themselves be regulated by helicases, such as DHX36 (aliases: G4R1 and RHAU), which possess the necessary activity to resolve these stable structures. G4s have been shown to both positively and negatively regulate gene expression when stabilized by ligands, or through the loss of helicase activity. Using Show less
Food allergies are common and are associated with substantial morbidity; the only approved treatment is oral immunotherapy for peanut allergy. In this trial, we assessed whether omalizumab, a monoclon Show more
Food allergies are common and are associated with substantial morbidity; the only approved treatment is oral immunotherapy for peanut allergy. In this trial, we assessed whether omalizumab, a monoclonal anti-IgE antibody, would be effective and safe as monotherapy in patients with multiple food allergies. Persons 1 to 55 years of age who were allergic to peanuts and at least two other trial-specified foods (cashew, milk, egg, walnut, wheat, and hazelnut) were screened. Inclusion required a reaction to a food challenge of 100 mg or less of peanut protein and 300 mg or less of the two other foods. Participants were randomly assigned, in a 2:1 ratio, to receive omalizumab or placebo administered subcutaneously (with the dose based on weight and IgE levels) every 2 to 4 weeks for 16 to 20 weeks, after which the challenges were repeated. The primary end point was ingestion of peanut protein in a single dose of 600 mg or more without dose-limiting symptoms. The three key secondary end points were the consumption of cashew, of milk, and of egg in single doses of at least 1000 mg each without dose-limiting symptoms. The first 60 participants (59 of whom were children or adolescents) who completed this first stage were enrolled in a 24-week open-label extension. Of the 462 persons who were screened, 180 underwent randomization. The analysis population consisted of the 177 children and adolescents (1 to 17 years of age). A total of 79 of the 118 participants (67%) receiving omalizumab met the primary end-point criteria, as compared with 4 of the 59 participants (7%) receiving placebo (P<0.001). Results for the key secondary end points were consistent with those of the primary end point (cashew, 41% vs. 3%; milk, 66% vs. 10%; egg, 67% vs. 0%; P<0.001 for all comparisons). Safety end points did not differ between the groups, aside from more injection-site reactions in the omalizumab group. In persons as young as 1 year of age with multiple food allergies, omalizumab treatment for 16 weeks was superior to placebo in increasing the reaction threshold for peanut and other common food allergens. (Funded by the National Institute of Allergy and Infectious Diseases and others; ClinicalTrials.gov number, NCT03881696.). Show less
Fibroblast growth factor receptor 1 (FGFR1) is a widely expressed, membrane-bound receptor that transduces extracellular signals from FGF ligands and cadherins, resulting in intracellular signals infl Show more
Fibroblast growth factor receptor 1 (FGFR1) is a widely expressed, membrane-bound receptor that transduces extracellular signals from FGF ligands and cadherins, resulting in intracellular signals influencing cellular growth, proliferation, calcium, and transcription. FGF21 and FGF2 stimulate the proliferation of tanycytes, specialized radial astrocytes along the ventricle of the hypothalamus, and influence metabolism. Tanycytes are in a privileged position between the cerebrospinal fluid, the blood supply in the median eminence, and neurons within nuclei in the hypothalamus. The effect of FGFR1 signaling upon tanycyte morphology and metabolism was examined in adult mice with conditional deletion of the Fgfr1 gene using the Fgfr1 Show less
Preclinical and genetic studies suggest that impaired glucose-dependent insulinotropic polypeptide receptor (GIPR) signaling worsens glycemic control. The relationship between GIPR signaling and the r Show more
Preclinical and genetic studies suggest that impaired glucose-dependent insulinotropic polypeptide receptor (GIPR) signaling worsens glycemic control. The relationship between GIPR signaling and the risk of cancers influenced by impaired glucose homeostasis is unclear. We examined the association of a variant in Show less
Mouse models of CLN3 Batten disease, a rare lysosomal storage disorder with no cure, have improved our understanding of CLN3 biology and therapeutics through their ease of use and a consistent display Show more
Mouse models of CLN3 Batten disease, a rare lysosomal storage disorder with no cure, have improved our understanding of CLN3 biology and therapeutics through their ease of use and a consistent display of cellular pathology. However, the translatability of murine models is limited by disparities in anatomy, body size, life span and inconsistent subtle behavior deficits that can be difficult to detect in CLN3 mutant mouse models, thereby limiting their use in preclinical studies. Here, we present a longitudinal characterization of a novel miniswine model of CLN3 disease that recapitulates the most common human pathogenic variant, an exon 7-8 deletion (CLN3Δex7/8). Progressive pathology and neuron loss is observed in various regions of the CLN3Δex7/8 miniswine brain and retina. Additionally, mutant miniswine present with retinal degeneration and motor abnormalities, similar to deficits seen in humans diagnosed with the disease. Taken together, the CLN3Δex7/8 miniswine model shows consistent and progressive Batten disease pathology, and behavioral impairment mirroring clinical presentation, demonstrating its value in studying the role of CLN3 and safety/efficacy of novel disease-modifying therapeutics. Show less
Electronic health record (EHR)-integrated digital personal health records (PHRs) via Fast Healthcare Interoperability Resources (FHIR) are promising digital health tools to support care coordination ( Show more
Electronic health record (EHR)-integrated digital personal health records (PHRs) via Fast Healthcare Interoperability Resources (FHIR) are promising digital health tools to support care coordination (CC) for children and youth with special health care needs but remain widely unadopted; as their adoption grows, mixed methods and implementation research could guide real-world implementation and evaluation. This study (1) evaluates the feasibility of an FHIR-enabled digital PHR app for CC for children and youth with special health care needs, (2) characterizes determinants of implementation, and (3) explores associations between adoption and patient- or family-reported outcomes. This nonrandomized, single-arm, prospective feasibility trial will test an FHIR-enabled digital PHR app's use among families of children and youth with special health care needs in primary care settings. Key app features are FHIR-enabled access to structured data from the child's medical record, families' abilities to longitudinally track patient- or family-centered care goals, and sharing progress toward care goals with the child's primary care provider via a clinician dashboard. We shall enroll 40 parents or caregivers of children and youth with special health care needs to use the app for 6 months. Inclusion criteria for children and youth with special health care needs are age 0-16 years; primary care at a participating site; complex needs benefiting from CC; high hospitalization risk in the next 6 months; English speaking; having requisite technology at home (internet access, Apple iOS mobile device); and an active web-based EHR patient portal account to which a parent or caregiver has full proxy access. Digital prescriptions will be used to disseminate study recruitment materials directly to eligible participants via their existing EHR patient portal accounts. We will apply an intervention mixed methods design to link quantitative and qualitative (semistructured interviews and family engagement panels with parents of children and youth with special health care needs) data and characterize implementation determinants. Two CC frameworks (Pediatric Care Coordination Framework; Patient-Centered Medical Home) and 2 evaluation frameworks (Consolidated Framework for Implementation Research; Technology Acceptance Model) provide theoretical foundations for this study. Participant recruitment began in fall 2022, before which we identified >300 potentially eligible patients in EHR data. A family engagement panel in fall 2021 generated formative feedback from family partners. Integrated analysis of pretrial quantitative and qualitative data informed family-centered enhancements to study procedures. Our findings will inform how to integrate an FHIR-enabled digital PHR app for children and youth with special health care needs into clinical care. Mixed methods and implementation research will help strengthen implementation in diverse clinical settings. The study is positioned to advance knowledge of how to use digital health innovations for improving care and outcomes for children and youth with special health care needs and their families. ClinicalTrials.gov NCT05513235; https://clinicaltrials.gov/study/NCT05513235. DERR1-10.2196/46847. Show less
Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and Show more
Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and East Asian descent, identified 42 genome-wide significant loci comprising 49 distinct association signals. Effect sizes were largest for stage 3/4 disease, driven by ovarian endometriosis. Identified signals explained up to 5.01% of disease variance and regulated expression or methylation of genes in endometrium and blood, many of which were associated with pain perception/maintenance (SRP14/BMF, GDAP1, MLLT10, BSN and NGF). We observed significant genetic correlations between endometriosis and 11 pain conditions, including migraine, back and multisite chronic pain (MCP), as well as inflammatory conditions, including asthma and osteoarthritis. Multitrait genetic analyses identified substantial sharing of variants associated with endometriosis and MCP/migraine. Targeted investigations of genetically regulated mechanisms shared between endometriosis and other pain conditions are needed to aid the development of new treatments and facilitate early symptomatic intervention. Show less
Retinoic acid (RA) is a ligand for nuclear receptors that modulate gene transcription and cell differentiation. Whether RA controls ectopic calcification in humans is unknown. We tested the hypothesis Show more
Retinoic acid (RA) is a ligand for nuclear receptors that modulate gene transcription and cell differentiation. Whether RA controls ectopic calcification in humans is unknown. We tested the hypothesis that RA regulates osteogenic differentiation of human arterial smooth muscle cells and aortic valvular interstitial cells that participate in atherosclerosis and heart valve disease, respectively. Approach and Results: Human cardiovascular tissue contains immunoreactive RAR (RA receptor)-a retinoid-activated nuclear receptor directing multiple transcriptional programs. RA stimulation suppressed primary human cardiovascular cell calcification while treatment with the RAR inhibitor AGN 193109 or These results establish retinoid regulation of human cardiovascular calcification, provide new insight into mechanisms involved in these responses, and suggest selective retinoid modulators, like acyclic retinoids may allow for treating cardiovascular calcification without the adverse effects associated with cyclic retinoids. Show less
Bisphosphonate drugs such as zoledronic acid (ZOL), used for the treatment of common bone disorders, target the skeleton and inhibit bone resorption by preventing the prenylation of small GTPases in b Show more
Bisphosphonate drugs such as zoledronic acid (ZOL), used for the treatment of common bone disorders, target the skeleton and inhibit bone resorption by preventing the prenylation of small GTPases in bone-destroying osteoclasts. Increasing evidence indicates that bisphosphonates also have pleiotropic effects outside the skeleton, most likely via cells of the monocyte/macrophage lineage exposed to nanomolar circulating drug concentrations. However, no effects of such low concentrations of ZOL have been reported using existing approaches. We have optimized a highly sensitive in vitro prenylation assay utilizing recombinant geranylgeranyltransferases to enable the detection of subtle effects of ZOL on the prenylation of Rab- and Rho-family GTPases. Using this assay, we found for the first time that concentrations of ZOL as low as 10nM caused inhibition of Rab prenylation in J774 macrophages following prolonged cell culture. By combining the assay with quantitative mass spectrometry we identified an accumulation of 18 different unprenylated Rab proteins in J774 cells after nanomolar ZOL treatment, with a >7-fold increase in the unprenylated form of Rab proteins associated with the endophagosome pathway (Rab1, Rab5, Rab6, Rab7, Rab11, Rab14 and Rab21). Finally, we also detected a clear effect of subcutaneous ZOL administration in vivo on the prenylation of Rab1A, Rab5B, Rab7A and Rab14 in mouse peritoneal macrophages, confirming that systemic treatment with bisphosphonate drug can inhibit prenylation in myeloid cells in vivo outside the skeleton. These observations begin a new era in defining the precise pharmacological actions of bisphosphonate drugs on the prenylation of small GTPases in vivo. Show less
Since RNA expression differences have been reported in autism spectrum disorder (ASD) for blood and brain, and differential alternative splicing (DAS) has been reported in ASD brains, we determined if Show more
Since RNA expression differences have been reported in autism spectrum disorder (ASD) for blood and brain, and differential alternative splicing (DAS) has been reported in ASD brains, we determined if there was DAS in blood mRNA of ASD subjects compared to typically developing (TD) controls, as well as in ASD subgroups related to cerebral volume. RNA from blood was processed on whole genome exon arrays for 2-4-year-old ASD and TD boys. An ANCOVA with age and batch as covariates was used to predict DAS for ALL ASD (n=30), ASD with normal total cerebral volumes (NTCV), and ASD with large total cerebral volumes (LTCV) compared to TD controls (n=20). A total of 53 genes were predicted to have DAS for ALL ASD versus TD, 169 genes for ASD_NTCV versus TD, 1 gene for ASD_LTCV versus TD, and 27 genes for ASD_LTCV versus ASD_NTCV. These differences were significant at P <0.05 after false discovery rate corrections for multiple comparisons (FDR <5% false positives). A number of the genes predicted to have DAS in ASD are known to regulate DAS (SFPQ, SRPK1, SRSF11, SRSF2IP, FUS, LSM14A). In addition, a number of genes with predicted DAS are involved in pathways implicated in previous ASD studies, such as ROS monocyte/macrophage, Natural Killer Cell, mTOR, and NGF signaling. The only pathways significant after multiple comparison corrections (FDR <0.05) were the Nrf2-mediated reactive oxygen species (ROS) oxidative response (superoxide dismutase 2, catalase, peroxiredoxin 1, PIK3C3, DNAJC17, microsomal glutathione S-transferase 3) and superoxide radical degradation (SOD2, CAT). These data support differences in alternative splicing of mRNA in blood of ASD subjects compared to TD controls that differ related to head size. The findings are preliminary, need to be replicated in independent cohorts, and predicted alternative splicing differences need to be confirmed using direct analytical methods. Show less
Chromatin is highly dynamic and subject to extensive remodeling under many physiologic conditions. Changes in chromatin that occur during the aging process are poorly documented and understood in high Show more
Chromatin is highly dynamic and subject to extensive remodeling under many physiologic conditions. Changes in chromatin that occur during the aging process are poorly documented and understood in higher organisms, such as mammals. We developed an immunofluorescence assay to quantitatively detect, at the single cell level, changes in the nuclear content of chromatin-associated proteins. We found increased levels of the heterochromatin-associated proteins histone macro H2A (mH2A) and heterochromatin protein 1 beta (HP1β) in human fibroblasts during replicative senescence in culture, and for the first time, an age-associated increase in these heterochromatin marks in several tissues of mice and primates. Mouse lung was characterized by monophasic mH2A expression histograms at both ages, and an increase in mean staining intensity at old age. In the mouse liver, we observed increased age-associated localization of mH2A to regions of pericentromeric heterochromatin. In the skeletal muscle, we found two populations of cells with either low or high mH2A levels. This pattern of expression was similar in mouse and baboon, and showed a clear increase in the proportion of nuclei with high mH2A levels in older animals. The frequencies of cells displaying evidence of increased heterochromatinization are too high to be readily accounted for by replicative or oncogene-induced cellular senescence, and are prominently found in terminally differentiated, postmitotic tissues that are not conventionally thought to be susceptible to senescence. Our findings distinguish specific chromatin states in individual cells of mammalian tissues, and provide a foundation to investigate further the progressive epigenetic changes that occur during aging. Show less
The nuclear hormone receptors liver X receptor alpha (LXRalpha) and LXRbeta function as physiological receptors for oxidized cholesterol metabolites (oxysterols) and regulate several aspects of choles Show more
The nuclear hormone receptors liver X receptor alpha (LXRalpha) and LXRbeta function as physiological receptors for oxidized cholesterol metabolites (oxysterols) and regulate several aspects of cholesterol and lipid metabolism. Seladin-1 was originally identified as a gene whose expression was down-regulated in regions of the brain associated with Alzheimer's disease. Seladin-1 has been demonstrated to be neuroprotective and was later characterized as 3beta-hydroxysterol-Delta24 reductase (DHCR24), a key enzyme in the cholesterologenic pathway. Seladin-1 has also been shown to regulate lipid raft formation. In a whole genome screen for direct LXRalpha target genes, we identified an LXRalpha occupancy site within the second intron of the Seladin-1/DHCR24 gene. We characterized a novel LXR response element within the second intron of this gene that is able to confer LXR-specific ligand responsiveness to reporter gene in both HepG2 and human embryonic kidney 293 cells. Furthermore, we found that Seladin-1/DHCR24 gene expression is significantly decreased in skin isolated from LXRbeta-null mice. Our data suggest that Seladin-1/DHCR24 is an LXR target gene and that LXR may regulate lipid raft formation. Show less
Yongjun Wang, Pamela M Rogers, Chen Su+3 more · 2008 · The Journal of biological chemistry · American Society for Biochemistry and Molecular Biology · added 2026-04-24
Cholesterol is required for normal cellular and physiological function, yet dysregulation of cholesterol metabolism is associated with diseases such as atherosclerosis. Cholesterol biosynthesis is reg Show more
Cholesterol is required for normal cellular and physiological function, yet dysregulation of cholesterol metabolism is associated with diseases such as atherosclerosis. Cholesterol biosynthesis is regulated by end product negative feedback inhibition where the levels of sterols and oxysterols regulate the expression of cholesterologenic enzymes. Sterol regulatory element-binding protein-2 is responsive to both sterols and oxysterols and has been shown to mediate the transcriptional response of the cholesterologenic enzymes to these lipids. Here, we show that the nuclear hormone receptor for oxysterols, the liver X receptor alpha (LXRalpha), regulates cholesterol biosynthesis by directly silencing the expression of two key cholesterologenic enzymes (lanosterol 14alpha-demethylase (CYP51A1), and squalene synthase (farnesyl diphosphate farnesyl transferase 1)) via novel negative LXR DNA response elements (nLXREs) located in each of these genes. Examination of the CYP51A1 gene revealed that both the SRE and nLXRE are required for normal oxysterol-dependent repression of this gene. Thus, these data suggest that LXRalpha plays an important role in the regulation of cholesterol biosynthesis. Show less
Type I human hepatic 3alpha-hydroxysteroid dehydrogenase (AKR1C4) plays a significant role in bile acid biosynthesis, steroid hormone metabolism, and xenobiotic metabolism. Utilization of a hidden Mar Show more
Type I human hepatic 3alpha-hydroxysteroid dehydrogenase (AKR1C4) plays a significant role in bile acid biosynthesis, steroid hormone metabolism, and xenobiotic metabolism. Utilization of a hidden Markov model for predictive modeling of nuclear hormone receptor response elements coupled with chromatin immunoprecipitation/microarray technology revealed a putative binding site in the AKR1C4 promoter for the nuclear hormone receptor known as liver X receptor alpha, (LXRalpha [NR1H3]), which is the physiological receptor for oxidized cholesterol metabolites. The putative LXRalpha response element (LXRE), identified by chromatin immunoprecipitation, was approximately 1.5 kilobase pairs upstream of the transcription start site. LXRalpha was shown to bind specifically to this LXRE and mediate transcriptional activation of the AKR1C4 gene, leading to increased AKR1C4 protein expression. These data suggest that LXRalpha may modulate the bile acid biosynthetic pathway at a unique site downstream of CYP7A1 and may also modulate the metabolism of steroid hormones and certain xenobiotics. Show less